Influence of crystallographic orientation and layer thickness on fracture behavior of Ni/Ni 3Al multilayered thin films

Abstract

Ni / Ni 3Al multilayers have been deposited epitaxially and non-epitaxially by UHV magnetron sputtering on <001> NaCl substrates. Two interfacial orientations were achieved: {001} Ni // {001} Ni 3Al, <100> Ni // <100> Ni 3Al and {111} Ni // {111} Ni 3Al, <110> Ni // <110> Ni 3Al. Under in-plane tensile loading, <001> oriented multilayers exhibit ductile fracture surface features but <111> oriented multilayers of the same layer thickness are predominantly brittle. For each orientation, the fracture surface features from 20 nm thick Ni and Ni 3Al layers appear to be as ductile or more ductile than those from 120 nm thick layers, but the plastic deformation appears to be more localized.